


Improvements

by NegaiFreak



Category: Highschool DxD (Anime), 僕のヒーローアカデミア | Boku no Hero Academia | My Hero Academia
Genre: BAMF Midoriya Izuku, F/M, Midoriya Izuku Has No Chill, Midoriya Izuku Has One for All Quirk, Multi
Language: English
Status: Completed
Published: 2020-11-25
Updated: 2020-11-25
Packaged: 2021-03-09 20:26:47
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings, No Archive Warnings Apply
Chapters: 2
Words: 3,292
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27711997
Author URL: https://archiveofourown.org/users/NegaiFreak/pseuds/NegaiFreak
Summary: Upon seeing just how far Issei has come as the Red Dragon Emperor, everyone's shocked to see his perversity on display once again. And when a certain someone gets completely fed up with it, what does it lead to? Why a sparring match against the heir to Bael family of course!
Relationships: Midoriya Izuku/Original Female Character(s), Rias Gremory/Hyoudou Issei
Kudos: 8





	1. PART I

"Well, I do want Issei to unleash his power..." Rias admitted with her arms underneath her ample chest, giving off an embarrassed blush before turning towards the armored teen as her breasts jiggled, "So go on, grab away!" she offered to him.

"FOR REAL?!" he exclaimed in shock, "HAHAHAAA!" he cackled with delight, "What?! With your cousin watching?!" he inquired further, though he wasn't about to say no...

"Wha...?" Ochaco uttered out in disbelief. She and the rest of Class 1-A were left baffled. After being invited to the Underworld by Rias, they were paying witness to a sparring match between Issei and Sairaorg Bael. And it was one to behold. At least until the moment when Asia suggested that the Red Dragon power up... by touching the Gremory heir's breasts.

"Is this actually happening right now?!" Denki exclaimed as a blush built upon his cheeks.

"We're about to witness a grope show?!" Minoru inquired as steam hissed out of his nostrils. In response to their perversity, Kyoka stabbed her right earlobe jack into the Electrification Quirk user's left ear, while Rachael whacked Minoru upside the head with a staff she summoned.

"Knock it off, you creeps..." the former of the two girls insisted as she too was blushing.

"It's gonna be a cold day in hell before that guy does something like that..." the requip user vowed as she balled her shaking fists. Overall, everyone just seemed stunned by what they were seemingly about to witness.

"Whoa, I didn't know you were into that sort of freaky thing!" Issei pointed out, "THANK YOU, PRESIDENT!" he exclaimed as he reached out his right hand.

"This... is quite a spectacle..." Alice remarked with a deep sigh.

"Indeed..." Tenya agreed, overhearing some growling nearby, "Bakugo, would you please calm down?" he insisted, thinking that the Explosion Quirk user was growing angry from watching what was about to happen as he turned to him, "I doubt that Hyodo will-" He stopped talking as he noticed that it wasn't Katsuki who had been growling. In fact, he was looking in surprise at who was actually growing angry: Izuku.

"D...Deku?" Natalie stuttered out worriedly, seeing her boyfriend clench his fists tightly as green sparks of electricity crackled around him.

"Hahaha..." Issei laughed as he slowly started walking towards Rias, prepared to touch her chest in order to gain the power he needed. But all of a sudden...

"SEATTLE..." Izuku's voice began to bellow.

"Huh?" the armored teen uttered, turning his head too late to see the freckled teen coming towards him with both feet first together like an arrow.

"SMMAAAAAAAAAAAAAAASSSSSSSSSSSSSHHHHHHHHHHHHHHHHH!" he roared as he slammed into Issei's head fiercely, making a burst of wind rush out before sending him tumbling away and crashing into one of the nearby pillars. Everyone was stunned, even Sairaorg and Sirzechs.

"Wow..." Mezo uttered out in amazement.

"That was insanely fast!" Eijiro exclaimed. Katsuki's eyes were shaking as he saw his rival land down on his feet. It had only been two months since their internship under Endeavor had begun. So to see Izuku with that kind of speed and power was insane.

"Ow..." Issei muttered out in agony as he sat up and rubbed his armored head.

' _Jeez... even though I wasn't paying attention, I thought being promoted to a Rook would at least let me take that better..._ ' he inwardly admitted as he let his armor disappear in a bright red light.

"What the heck's your problem, Izuku?!" he shouted to the approaching freckled teen.

"SHUT UP!" he bellowed, causing Issei to immediately silence himself as his eyes jolted open. Everyone in Class 1-A was in disbelief over Izuku's sudden shift in tone. He was angry. Very angry. "I was rooting for you back there, you know..." he pointed out green sparks of electricity crackled around him still, "You were giving it your all, even though you seemed like you were in a bind..." he continued, balling his trembling fists, "AND THEN YOU TRY TO PULL A STUPID STUNT LIKE THAT?!" he roared angrily in question, "WHAT THE HELL IS THE MATTER WITH YOU?!" he asked on loudly. The whole of Class 1-A watching was left floored by this sudden outburst.

"Uh..." Natalie uttered out as a trickle of blood came out of her left nostril.

"Hey, Nat..." Kyoka said upon noticing. Letting out a meek squeak, the Dragon Slayer immediately covered her bleeding nose.

"Sorry!" she apologized quietly.

"HAHAHAHAHAHA!" Sairaorg suddenly started laughing, catching their attentions. Izuku and Issei looked over in confusion.

"What's... so funny?" the latter asked, arching an eyebrow.

"I get it now," the high-ranking devil responded with crossed arms, "You get powered up from touching Rias' knockers!" he concluded. Hearing that made Izuku growl again as he whipped his head back to glare at Issei, who flinched in surprise. "Let's end our fight here for now," Sairaorg insisted.

"B-But I'm not finished yet...!" Issei stuttered as a complaint.

"That's what she said," the high-ranking devil quipped in response, going over and crouching down in front of the Red Dragon as he placed his left hand onto his shoulder, "If we keep at it, one of us'll probably bite the bullet," he pointed out, "And besides..." he continued, "I think you're on the brink of an evolution..." he mentioned, much to the perverted teen's surprise as he blinked, "So until you reach that level before the Rating Game, we'll hold off on our battle," he decided, holding out his right fist to Issei.

"Yeah, sure," he replied, bumping his fist with his own to metaphorically seal the deal.

"Huh..." Rias sighed with relief, fortunate that she didn't have to suffer an embarrassing public display... even though she wouldn't have minded...

"Now then..." Sairaorg continued, standing up and turning to Izuku, "Issei said your name was Izuku, right?" he guessed while raising an eyebrow.

"Y-Yes, sir!" the freckled teen stammered, stiffening up, "I'm Izuku Midoriya!" he greeted with a slight bow, causing the high-ranking devil to chuckle.

"That speed and power was quite impressive, especially for someone who isn't even a devil..." he pointed out, crossing his arms over his chest, "I'm curious to see just _how_ strong you really are..." he admitted to his surprise, "Sirzechs," he called out to the Underworld King, "would you allow me to have one more battle with this human?" he asked of him.

"Wait, what?!" Izuku exclaimed in shock.

"So long as he accepts the challenge, I don't see why not," Sirzechs responded assuredly.

"Wait, that guy wants to fight Deku?!" Ochaco exclaimed.

"Quite the surprise..." Yuga commented with his right hand upon his chin.

"Yeah, but that guy was punching left and right like All Might..." Hanta pointed out, "The dragon dude was barely able to get some licks in, so what's Midoriya supposed to do?!" he wondered out of concern.

"It'd probably be in his best interest to forfeit this challenge..." Momo confessed with her arms crossed, "There's no way I can see him winning..." she added. Despite most of the class wanting to keep faith in the freckled teen, he was being challenged by someone who appeared to be just as capable as some of the strongest people in the multiverse. But even so...

"If you're the one offering me a chance to battle you, I can't refuse," Izuku stated, taking a ready stance, "I accept!" he declared firmly as green sparks of electricity crackled mightily around him.

"Izuku..." Issei uttered out in amazement as his eyes shook.

"My, my..." Akeno repeated with a giggle, "Once again, it looks like Izuku's going to upstage Issei..." she noted curiously.

"I wonder if he'll last longer..." Yuto said as he grinned a little.

"Good luck, Deku!" Ochaco cried out from the viewing section.

"Do your best!" Asia cheered, "Even if you are up against a high-ranking devil!" she pointed out. Balling his fists tightly, Izuku took a deep breath.

' _Battling against someone with raw power that's similar to All Might's..._ ' he noted inwardly, ' _If I'm gonna get even stronger, I'll happily take on that challenge!_ ' he decided through his thoughts.


	2. PART II

' _One For All: Full Cowling..._ ' Izuku began through his thoughts as red lines of energy built up along his body with green sparks of electricity crackling around it, ' _Thirty Percent!_ ' he bellowed inwardly as a burst of wind rang out.

"Hm," Sairaorg chuckled, clenching his fists, "Give me all you got, kid!" he insisted firmly.

"I will!" the freckled teen promised with a nod. Watching from the viewing section, those in the Gremory household and the Class 1-A students watched on with varying levels of concern.

"After seeing how Lord Sairaorg dealt with Issei, I doubt Izuku has a better chance..." Xenovia admitted.

"Yeah..." Gasper agreed, "It's almost like a level thirty player going up against a boss who's level one hundred in a video game!" he pointed out.

"This guy's basically like All Might to boot..." Rikido mentioned, "No way is Midoriya leaving that ring without a few scrapes..." he added grimly.

"A few scrapes?" Hanta repeated, "His bones are gonna get crushed if he takes even a single hit from that guy!" he noted worriedly. Meanwhile, Natalie looked at the firm expression her boyfriend had on his face.

' _If he's willing to take one someone that's on the same level as maybe All Might was..._ ' she started to realize, ' _then he has a plan,_ ' she told herself, clutching her hands together over her chest.

"You may begin," Sirzechs said, signaling the match's start. Hearing that made Izuku jolt forward instantly.

"Whoa, holy shit!" Issei exclaimed in surprise, blinking rapidly to see the freckled teen make his way behind Sairaorg. However, the high-ranking devil turned his head, seeing him reel his right leg back. He attempted a roundhouse kick to his foe's head, but it was blocked as he threw his right arm, making a burst of wind rush out.

"That was a quick reaction..." Tsuyu pointed out.

"So even Izuku's speed is picked up on by this guy..." Raya realized nervously. Jumping back, Izuku landed down and took a deep breath. He hurriedly started jumping around the area, bouncing off of walls and pillars to gain momentum.

"Bakugo," Shoto chimed in, catching the attention of the Explosion Quirk user, "it seems like Midoriya's getting ahead of us again," he pointed out.

"Humph..." Katsuki huffed, stuffing his hands into his pockets, "Yeah, we'll see if that damn nerd can take a hit..." he muttered, watching on intently. Izuku was still jumping around.

' _I might not have Hyodo's defensive power, especially as he was promoted to a Rook during his fight..._ ' he noted inwardly as he attempted to land a fierce kick with his left foot extended out at his foe, ' _but I can make up for that with my speed!_ ' he exclaimed through his thoughts, striking the high-ranking devil upside the head. However, he knew that wouldn't deter him as he noticed his foe reeling his left arm back for a backhanded attack. Reacting quickly, Izuku hopped back and ducked down, narrowly evading getting struck by the blast of pressurized wind that came about from Sairaorg merely swinging his arm out. However, his tie was torn off as it blew up into the stands, being caught by Ochaco.

"That was a good attack..." the Bael Family heir admitted as he rubbed his chin curiously, "And your reaction time's quite good," he complimented in addition.

"Thank you," Izuku responded, "But I'm not finished yet!" he declared as the sparks around him crackled mightily.

"Good," Sairaorg replied, readying his fists. Watching on intently, Issei had a shocked look on his face.

' _I hate to admit it, but I wish I had a training regimen like Izuku's..._ ' he inwardly confessed, ' _He's a lot better at thinking on his feet while managing to bring out the best he can of his power..._ ' he noted to himself. Everyone watched on in anticipation for the next move. Izuku held his fists up like a boxer... and raised his right leg.

"Hm?" Sairaorg uttered in confusion as he blinked.

"The heck is that stance?" Eijiro wondered as he arched an eyebrow.

"I don't know..." Irina answered while blinking.

"It... kinda looks familiar..." Rachael admitted before gasping in surprise. Sairaorg had reared back his right fist and thrusted it forward to unleash a blast of air that was about to crash onto Izuku.

' _Forty-Five Percent!_ ' he exclaimed, thrusting his leg down in an instant. The gust of wind pressure he created blew him upwards, making him evade the incoming blast as everyone gasped in surprise. He then reeled his leg back.

"Saint Louis Smash..." he began as he swung it out, "AIR FORCE!" he roared, firing off his own blast down onto Sairaorg, enveloping him within a plume of dust.

"Whoa!" Issei yelped.

"I'm impressed," Rias admitted, "Izuku's holding his own against the heir to the Bael Family and managing to catch him off guard," she pointed out. The Red Dragon inwardly agreed. He held his own, but he was a devil that had an armored suit on. Izuku had just his body. And he was doing a good job of keeping himself out of harm's way.

"Haha!" Sairaorg laughed from within the dust cloud, "Now that's really impressive!" he complimented, "You're able to create blasts of wind pressure with your power as well!" he noted, not noticing the figure running around in behind, "It may not be as powerful as mine, but-" He stopped talking as he heard footsteps, whipping around too late as Izuku landed a straight jumping kick to his stomach with his left foot. "Ergh...!" he grunted out, clenching his teeth.

' _Don't let up!_ ' Izuku commanded to himself, gritting his own teeth as he swung his right foot to strike the high-ranking devil at his chin, followed by flipping onto his hands and landing two more spin kicks to make him stumble back.

"Amazing..." Rossweisse remarked as she blinked rapidly.

"It makes you wonder if Issei could've done something like that in the last battle..." Xenovia commented.

"Midoriya's known for thinking on his feet..." Mashirao noted with crossed arms.

"And he's doing crazy good right now!" Mina added excitedly.

"Yeah, go Midoriya!" Toru cheered. The freckled teen let out a fearsome yell as he hopped over and thrusted his right foot fiercely into Sairaorg's face, making him appear to wince as a bit of blood spurted from his nose.

"Holy crap..." Issei uttered out in disbelief. But then he saw the high-ranking devil reel his right fist back. Izuku took notice as well and grimaced.

' _Shoot!_ ' he yelped through his thoughts. He would've been struck if not for the black tendril that emitted from in between his knuckles and wrapping around a nearby pillar, yanking him away in the nick of time as the force of the attempted uppercut sent out a blast of pressurized wind high into the sky. Sairaorg gave off a grin as he glanced over to the freckled teen.

"You're full of surprises, Izuku Midoriya!" he noted excitedly as his opponent breathed heavily while retracting the black tendril.

' _Great... I was saving the Blackwhip for later..._ ' he muttered inwardly, steadying his breathing, ' _So now I'll have to do what I can with it!_ ' he realized, clenching his teeth before dashing forward. He jumped around the arena again, building up momentum.

"Incredible..." Tenya uttered out, "Normally, a hero would turn away and seek help against such a foe..." he noted.

"But Deku's giving it his all since that guy asked for it!" Ochaco pointed out, balling her fists and grinning.

"Yeah, that's peak manliness!" Eijiro remarked.

"Ergh..." Katsuki growled in frustration. Sairaorg's eyes moved left and right to keep track of Izuku as he bounced around. He finally found himself right above and behind the high-ranking devil. However, he took notice.

"I guess it's finally time to settle this!" he concluded, turning around and reeling his right fist back. The freckled threw out his left fist, making multiple black tendrils shoot out restrain Sairaorg's arm, much to his surprise. Not only that, it allowed for Izuku to yank himself down instantaneously to his foe.

"TAKE THIS!" he roared, slamming his right foot fiercely into his opponent's face as a burst of wind rang out.

"Whoa!" Irina yelped.

"That looked like a solid hit..." Xenovia noted with shaking eyes. Everyone was in shock over how Izuku had managed to land such a strong blow. But it didn't seem to matter to Sairaorg as he readied his left fist.

"IS THAT THE BEST YOU'VE GOT?!" he wondered loudly in challenge. Izuku clenched his teeth together.

"I'M NOT FINISHED YET!" he roared as a response, making more black tendrils emerge from his right knuckles, wrapping around and restraining the high-ranking devil's left arm. He then reared his right foot back before landing a powerful series of rapid kicks with it to his opponent's face, yelling all the while.

"Whoa..." Issei uttered out in disbelief.

" _I'm just as shocked as you..._ " Ddraig commented, getting his attention, " _To think that a human like Izuku would manage to fight with a high-ranking devil is astounding..._ " he admitted, " _Imagine how powerful he could still become..._ " he added as a suggestion, causing the Boosted Gear user to blink in surprise. Everyone was astonished by the showing, even Sirzechs. For he knew how strong and capable Sairaorg was. So Izuku was definitely leaving an impression. He reeled his right leg back one last time as the black tendrils tightened their hold on his foe's arms.

"Shoot Style..." he began to bellow, "BOSTON..." he continued, making the black tendrils dissipate instantaneously just as he slammed his foot into his opponent's face, "SMAAAAAAAAASSSSSSSSSHHHHHHHHHHHHHH!" he roared out, sending him tumbling back along the arena before he crashed into a pillar. Everyone was stunned. And trickles of blood were coming out of Natalie's nose.

"Hey, Natalie!" Kyoka yelped upon noticing.

"Eep!" the Dragon Slayer squeaked, blushing as she covered her bleeding nostrils with her hands, "Not again..." she muttered out quietly.

"Huh... huh..." her boyfriend breathed in exhaustion upon landing down, keeping himself in a ready stance.

' _Man, talk about badass..._ ' Issei inwardly noted as he stared out at the freckled teen, ' _I'd hate to be the guy who pisses him off..._ ' he admitted through his thoughts, ' _Though honestly... I am that guy..._ ' he realized as he gulped.

"Now that was _really_ impressive!" Sairaorg's voice remarked as he stepped out from the cloud of dust, "Your speed an power are definitely on par with most household devils," he pointed out, "That said, I think you're one of the strongest humans I've ever had the pleasure of fighting," he added in admittance, "So I'll grant you a taste of my strength!" he declared, thrusting his right forward in an instant. Izuku had no time to react as the blast of wind pressure that rushed by ripped off the right half of his white shirt to reveal the black compression sleeve upon his arm. Sairaorg noticed, blinking in surprise. Hearing the crashing sound in the background, the freckled teen glanced back and gasped to see the gaping hole in the arena.

"Holy crap..." he uttered out in disbelief.

"I think that's enough for now," the high-ranking devil said, catching his attention as he turned to see him approach, "From what I can tell, you too are on the verge of an evolution," he pointed out as he placed his left hand onto Izuku's shoulder, "So when you reach that point, will you be willing to battle me again?" he asked of him. Blinking in surprise for a moment, the freckled teen pulled off a smile.

"Of course!" he responded firmly with a nod.

**Notes for the Chapter:**

> Wanna see more awesome crossover content? Come and check out my FanFiction page!
> 
> https://www.fanfiction.net/u/3776529/NegaiFreak

**Author's Note:**

> Wanna see more awesome crossover content? Come and check out my FanFiction page!
> 
> https://www.fanfiction.net/u/3776529/NegaiFreak


End file.
